street carnival was introduced by the portuguese in the sixteenth century with entrudos, games that already existed in villages, in general among families and friends.

typically, these games involved the use of small wax balls containing lemon-scented water that people would throw jokingly at one another.

on some occasions, the wax balls did not contain lemon-scented water, and did in fact contain foul smelling (dirty) substances.

sujo means 'dirty' in portuguese, thus some say the name derives from the fact that the participants were 'dirty' from the wax balls and the liquids in them.